There currently exists an increasing interest in the tracking of serial manufactured metal tubes, not only as regards the internal tracking within the premises but also after such tubes are delivered. There exists a large variety of identification and tracking methods which involve printing of symbols (numbers, bar codes, brands, etc.,) by means of electrolytic attack, machining, laser, identification bands, releasable labels, electronic cards or modules, which may be implanted inside or outside the metal tube.
However, codes printed on a metal surface become eventually useless due to the deterioration of identification marks, which become dirty or are deleted until they disappear, rendering viewing thereof difficult. At present there do not exist durable prints on metal tubes, due to the harsh conditions of tubes manufacturing processes, transport requirements and extended exposures to humidity and other environmental conditions. The above applies both to pipeline and casing tubes. As regards tubes intended for production tubings, same may be reused, and thence more durable marks will be required, which marks should also support wells operative conditions, namely temperature, hydrocarbons and aqueous solutions presence, etc.
Also, electronic identification methods are widely used at present with the purpose of tracking and identifying personal articles, serial products, mail, animals, baggage, wastes, etc. These electronic methods employ devices including an integrated circuit in order to transport information corresponding to the article one wishes to track.
Particularly, in the case of tubes manufacturing, radio frequency identification (RFID) technology would not only provide tubes identification but also data storage and reading capacity without the need of contacting tubes. Data storage allows tracking of those characteristics specifically pertaining to processes and manufacturing.
It is known that these kind of structures are subject to adverse conditions during handling, transport and use, and thence it is required a high performance identification system, particularly in the case of hostile well operation conditions (high temperature, exposure to solvents, hydrocarbons, hot aqueous solutions, etc.). Further, as metal tubes could be used for other services after their use in wells, a durable identification technology is needed, able to store data throughout the life of the metal tube.
Documents JP 11352243, JP 2000065510 and JP 2003022428 disclose a detection element which is buried along with a metal body, said detection element including a radio frequency identification (RFID) circuit which is attached to the external surface of said metal body by means of an adhesive tape, said detection element including an electromagnetic screen between said metal body and said RFID circuit. The purpose thereof is to accurately identify a metal body, such as a metal tube, without variations of the resonance frequency which is sent from the identification device, which activates a radio frequency identification (RFID) circuit and Q gain of a coil, even when the identification device is fully attached to the metal body.
Document JP 2004245963 discloses a long tube within which a large number of cables pass through, said tube including a plurality of radio frequency identification (RFID) labels, said labels being suitable spaced along said tube, in order to easily and accurately identify a single certain cable among a plurality of cables. As the identification labels are located within the tube body, their heat resistance is higher, and labels are not affected by external temperatures.
Document JP 2004247090 discloses a hollow tubular body intended to accommodate cables, said tubular body being able to store a large quantity of information regarding the cable, without such stored information becoming indistinguishable in the course of time. Said elongated body comprises a plurality of radio frequency identification (RFID) labels which are spaced from each other a predetermined distance along said body.
Other documents such as U.S. Pat. No. 4,822,987, U.S. Pat. No. 4,944,856, U.S. Pat. No. 4,960,984, U.S. Pat. No. 4,978,917, U.S. Pat. No. 5,477,023, U.S. Pat. No. 5,777,303, U.S. Pat. No. 5,844,802, U.S. Pat. No. 6,016,255, U.S. Pat. No. 6,036,101, U.S. Pat. No. 6,122,704, U.S. Pat. No. 6,330,977 and U.S. Pat. No. 6,349,881 refer to the identification and tracking of metal tubes by means of other detection elements such as for instance laser identification labels or bar codes, printing by chemical attack, by etching, semi-conductive integrated circuits attached by means of probes, electronic cards and the like.
As previously mentioned, durability of the above identification and tracking devices is very limited, due to the environmental hostility once tubes are delivered from the manufacturing plant, because of storage, handling, transport and use in wells; reading of said identification elements being further susceptible of being affected by the electromagnetic shielding generated by metal tubes on which such elements are fixed. On the other hand, in those cases in which an electromagnetic screen or shield is used in order to attenuate said shielding effect, the identification element becomes voluminous, it being then subject to transport and handling risks as already mentioned.
Thus, it is necessary to create a device for the identification of metal tubes from the manufacturing plant to the end of the life of said tubes, such device being capable of solving all of the art problems known up to this day. It is also necessary to be able to store and retrieve data pertaining to such tubes, including evolution thereof throughout their life.